Open Access

Francesco Gardumi, Abhishek Shivakumar, Robbie Morrison, Constantinos Taliotis, Oliver Broad, Agnese Beltramo, Vignesh Sridharan, Mark Howells, Jonas Hörsch, Taco Niet, Youssef Almulla, Eunice Ramos, Thorsten Burandt, Gabriela Peña Balderrama, Gustavo Nikolaus Pinto de Moura, Eduardo Zepeda, Thomas Alfstad

• In the last decades, energy modelling has supported energy planning by offering insights into the dynamics between energy access, resource use, and sustainable development. Especially in recent years, there has been an attempt to strengthen the science-policy interface and increase the involvement of society in energy planning processes. This has, both in the EU and worldwide, led to the development of open-source and transparent energy modelling practices.This paper describes the role of an open-source energy modelling tool in the energy planning process and highlights its importance for society. Specifically, it describes the existence and characteristics of the relationship between developing an open-source, freely available tool and its application, dissemination and use for policy making. Using the example of the Open Source energy Modelling System (OSeMOSYS), this work focuses on practices that were established within the community and that made the framework's development and application both relevant and scientifically grounded. Keywords: Energy system modelling tool, Open-source software, Model-based public policy, Software development practice, Outreach practice